Cave-in: Crews lost half a day after a drill broke. It's unknown if any of the nine men still are alive. Last sounds of life were heard Thursday.

SOMERSET, Pa. — Losing 18 precious hours because of a broken drill, rescuers began burrowing a second escape shaft Friday in their dogged attempt to free nine miners hemmed in for nearly two days deep in a water-saturated coal mine.

By day's end, both mechanical borers were digging toward the miners, cut off 240 feet below the surface of the Quecreek Mine. The first rig, repaired with a 1,500-pound metal bit flown in by helicopter, was still more than 100 feet from the trapped men in late evening. The second rig, operating all day but making halting progress through bedrock, was about 200 feet away.

Rescuers did not know if any of the men still were alive. The only evidence of life below has come from the succession of nine taps on a metal pipe--miners' code signaling the presence of survivors--last heard Thursday afternoon.

On Friday, there was only silence underground.

"It's disheartening when you lose communication," said Dave Lauriski, head of the U.S. Mine Safety and Health Administration, one of several federal agencies involved in the rescue effort.

Sheets of rain slanted down much of the day as worried public officials, engineers, mining company workers and volunteers massed around drenched crews straining to master their balky machines and make up for lost time. At a nearby fire station, relatives of the trapped men gathered to wait and pray, joined by concerned neighbors, some of whom had lost loved ones in similar disasters.

"If anybody can survive, I would place my bet they'll make it out," said Mike Maurer, 44, whose brother-in-law is trapped miner Robert Pugh, 50. Maurer and other local miners identified eight of the trapped men as Pugh, John Unger, Randall Fogle, Thomas Foy, Blaine Mayhew, Ron Heilman, John Philipe and Mark Poperneck.

Even with both drills churning, Schweiker said just before dusk that rescuers would not close in on the trapped crew for at least six hours. Other officials said they were uncertain when the drills would be able to pierce the dense layers of limestone, shale, sandstone and finally, coal pillars. "Bottom line, it's going to take long," Schweiker conceded.

Rescuers sought to protect the trapped miners from potentially fatal hypothermia or decompression.

Six powerful blowers pumped air heated to 190 degrees down through holes punched into the earth to keep the men warm, while the Navy trucked in nine portable hyperbaric chambers to protect them from the "bends," a lethal sickness they could contract from high underground water levels.

Navy Capt. Henry Schwartz, a specialist in underwater medicine, said that air pressure building inside the 4-foot-high coal seam could rise to rates similar to those experienced by divers 40 feet underwater. Lethal bubbles could develop in the miners' blood during their ascent to ground level, he said.

Officials said they have concluded that the 4-foot-high chamber where the miners were trapped was waterlogged but probably contained enough air to keep them alive. Their helmet lantern batteries likely were spent, said Joseph A. Sbaffoni, chief of the state's Bureau of Deep Mine Safety, leaving them in darkness inside the coal-lined crawlspace.

Sam Darrigo, 72, a veteran of western Pennsylvania mines, said the trapped men would be "in total darkness down there now. That's the hardest part. But if they're in a dry area, if they've found an air bubble, they could get out."

A large air bubble could protect the trapped men from body-chilling hypothermia, particularly if the temperature inside the seam was raised by drafts of hot air pumped from above, said Raja Ramani, professor of mining engineering at Penn State University.

"The concern is that the coal seam is only 52 inches high and these miners may not have adequate head room," Ramani said. "But as long as there is breathable atmosphere, hypothermia and other problems should not be serious if they can be reached in a reasonable amount of time."

For much of the day, optimism was about the only thing keeping rescuers going. On the verdant hill where the drilling rigs rumbled, an army of volunteers had little else to do except rehearse its role in the planned rescue and pray that the chance would come.

"People are sitting here, watching and hoping and praying," said Terry Smith, 45, a firefighter assigned to a rescue detail if the miners are found alive. "That's all we've got left: hoping and praying."

Smith had a personal stake in his duty. A coal miner for 27 years who quit because of an injury a few years ago, Smith knows seven of the trapped men. Two of them, Unger, 52, and Pugh, are his close friends.

As he trudged toward the Sipesville Volunteer Fire Department headquarters, where the miners' families kept a vigil, Smith said that when he crawled down deep into the coal caverns, he constantly feared being trapped.